2 Answers
2

1) Downlaod the YSlow extension to Firefox, and install it. This will let you test on a number of different items that can suggest why your site may be slow. This doesn't currently look to be your current big problem right now, though.

2) Install the Firebug extension to firefox. The 'Net' tab of firebug tells you how long every document took to download. your core page is taking 5 seconds, and for some reason system.css is taking almost as long, which is unusual in that it's a static file.

Beyond that, some suggestions: You're almost certainly not using some of Drupal's performance options, such as caching, and I would suggest using memcache to speed the site up as well. (See http://drupal.org/project/memcache)

It really looks like you've got a query that's taking too long. It seems to me that the slow query log is what's going to be the most useful tool - it'll tell you where you need to optimize your site. Do note that mysql tends to use the first index on a table that it finds in the WHERE clause instead of the fastest, and as such a query like "WHERE type='story' AND status = 1" is faster than "WHERE status = 1 AND type='story'", because there type index filters the data better than the status one. (And Views tends to put the items in the where clause in the same order that they're in the Filter section.)